Sediment has been recognized as one of the most significant water quality impairments in the United States. Historically, soil erosion was primarily considered an agricultural issue, but construction sites are receiving increased attention as more land is being developed and there is greater awareness of water quality issues. While numerous erosion and sediment control products and practices are being used in the field to reduce soil loss from construction sites, there are only few standardized tests to evaluate the effectiveness of most of these practices, and such tests are relatively complicated. Thus, there remains a need for a relatively simple test procedure for evaluating sediment control products.
As a result, silt fences have become a commonly accepted erosion and sediment control product. Most silt fences are constructed of woven geotextile fabrics, sometimes reinforced by wire, supported by metal posts. Silt fences help to impound runoff and to increase sedimentation by filtering the fluid as it flows away from the development site. While not wishing to be bound by theory, it is believed that the silt fence initially removes silt and sand particles from overland flow through filtration of the large particles, and as the larger particles block the pores in the silt fence, runoff begins to pool or “pond” behind the fence to promote sedimentation.
Installation and maintenance is a problem commonly reported with silt fences. The geotextile fabric typically is attached with fasteners to wooden or metal stakes driven into the ground to secure the fabric in position to collect and filter dirt and debris from runoff water flows. The fasteners typically include staples, hooks, rings, or similar devices that are inserted through the fabric to attach it to the stakes. However, due to their relatively thin, porous nature, geotextile fabrics usually do not exhibit enough tensile strength to avoid pulling and tearing at the insertion or puncture points of the fasteners as water, direct, and debris bear against the fabric as runoff flow passes therethrough. When the fabric pulls and tears, it frequently fails to control erosion effectively. Consequently, there is a need for geotextile fabrics and sheets that resist tearing and pulling at fastener insertion points. Additionally, undercutting and flanking of the fence can occur due to improper installation, and overtopping can occur when silt fences are improperly located in concentrated flow conditions or when the flow rate through the fence is inadequate.
Thus, there remains a need for a sediment control product, for example, a silt retention material and/or silt retention system, that features enhanced durability while effectively promoting sedimentation, thereby reducing maintenance and improving overall performance.